Rookie Johnny Gaudreau and sophomore Joe Colborne were in the spotlight because of costly mistakes in the Flames' 4-2 loss to the Ducks that's left them trailing the Western Conference semifinal three games to one.
"When you talk about experience, those situations will make them better," said Hartley. "Tonight we're paying a big price but at the same time, those guys will be a big part of our team. They made us win way more games than they made us lose."
Seventy-two hours earlier, they both scored key goals in Calgary's 4-3 overtime win that cut Anaheim's series lead to 2-1.
Gaudreau — as the last man back — had the puck stolen by Andrew Cogliano, who worked a give-and-go with Kyle Palmeiri that resulted in Cogliano beating Karri Ramo with the tying goal at 16:42 of the second period.
At the intermission, Gaudreau apologized to Ramo.
"I talked to him in the locker room after the period and I took full responsibility," said Gaudreau, who is one of seven rookies to suit up in the post-season for Calgary. "I didn't really see (Cogliano), he came out of nowhere and picked my pocket and gave them a 2-on-0 and I hung him out to dry."
Then, as the second period ended, Colborne got his stick up in the face of Francois Beauchemin. With the veteran defenceman suffering a small cut, a double-minor for high-sticking was assessed.
Already 1-for-2 with the man advantage in the game, Anaheim didn't need long to break the tie and take the lead for good on Beleskey's goal at 1:11.
"That's on me. I definitely let the boys down there," said Colborne. "That's frustrating. Just trying to play on that line of being physical."
Hartley shrugged off the two mistakes as part of growing up in the NHL.
"Where would we be without Johnny Gaudreau? We can talk about Johnny, we can talk about Colbie's penalty. They will learn. They are two great kids," said Hartley. "It's sad because we paid on both of those situations."
Calgary finally got its first power play of the night at 6:53 of the third and it became a 56-second, two-man advantage when Cogliano was whistled for holding Gaudreau.
The Falmes, however, squandered away the opportunity.
"There were a few shots where we missed the net and we got the puck out by ourselves just rimming it, missing nets," said Gaudreau.
Calgary must now win three straight against the Pacific Division champions and that will have to include two victories at Honda Center, where the Flames haven't won since 2006 — losing their last 21 visits.
"We've got nothing to lose, we're going to leave it all out there," said Mikael Backlund. "All year, people have been doubting us and not believing in us but we have. It's going to be the same now. We've just got to be really strong and take it game by game, focus on the next game and even just shift by shift."
Game 5 goes Sunday night.
"I know that everyone that's going to get on the plane together believes that we can go and get Game 5 and force a Game 6 over here," said Hartley. "That's the identity of this organization all year and we're not going to change. It's a tough loss tonight. We're going to swallow it and tomorrow we'll be back at work."